Add a tube to a round footing below it.
⚙️Calculation Parameters
📊Calculated Output
How Tube and Round Footing Calculator Works?
To combine a tube and a round footing, the Tube and Round Footing Calculator adds 2 cylinders that do not overlap: the footing pad below and the tube above. The process takes 4 steps.
Enter the footing
Type the round pad diameter and thickness.
Enter the tube
Type the tube diameter and the height from the top of the pad to the top of the pier.
Avoid double counting
The tube height starts at the top of the pad, so the 2 volumes do not overlap.
Read the total
The calculator sums the 2 parts and shows each share in cubic feet (ft³) and bags.
Tube and Round Footing Calculator Formula
The Tube and Round Footing Calculator stacks 2 cylinders.
Footing
V_f = π × (D_f ÷ 24)² × (t ÷ 12)Pad diameter D_f and thickness t.
Tube
V_t = π × (D_t ÷ 24)² × (H_t ÷ 12)H_t starts at the pad top.
Total
V = V_f + V_tNonoverlapping sum.
Worked example: 24 in × 8 in pad with 12 in × 40 in tube
- V_f = 2.094 ft³
- V_t = 2.618 ft³
- V = 4.712 ft³ → 8 bags of 80 lb
Tube and Round Footing Calculator Conversion Table
The tube and round footing conversion table lists 5 combined piers with the tube, pad and total volumes.
| Tube | Round pad | Tube ft³ | Pad ft³ | Total ft³ | 80 lb bags |
|---|---|---|---|---|---|
| 10 × 40 in | 20 × 8 in | 1.82 | 1.45 | 3.27 | 6 |
| 12 × 40 in | 24 × 8 in | 2.62 | 2.09 | 4.71 | 8 |
| 12 × 36 in | 24 × 12 in | 2.36 | 3.14 | 5.50 | 10 |
| 16 × 48 in | 30 × 10 in | 5.59 | 4.09 | 9.68 | 17 |
| 18 × 48 in | 36 × 12 in | 7.07 | 7.07 | 14.14 | 24 |
Pour the pad and tube in one placement, if the design allows, to avoid a cold joint.
What is Tube and Round Footing Calculator?
A Tube and Round Footing Calculator is a combined calculator that totals the concrete for a Sonotube pier sitting on a wider round footing pad.
A pad-and-tube pier puts a wide base under a narrow column. The calculator keeps the 2 parts separate, so the tube height is not counted twice through the pad. A 12 in × 40 in tube on a 24 in × 8 in pad needs 4.71 ft³, with 44% of that in the pad.
The split shows how much concrete the pad adds and helps compare a pad design with a plain deeper tube.
What are the uses of Tube and Round Footing Calculator?
There are 4 main uses of the Tube and Round Footing Calculator.
Spread-footing piers
Builders pour a round base and set a tube on top.
Monolithic pours
Crews fill pad and tube in one pour with the tube suspended.
Design comparisons
Designers compare pad-and-tube with tube-only piers.
Accurate orders
Estimators total both parts without overlap.
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